|Publication number||US7760607 B2|
|Application number||US 12/019,643|
|Publication date||Jul 20, 2010|
|Filing date||Jan 25, 2008|
|Priority date||Jul 23, 2004|
|Also published as||US7349312, US20060028949, US20080112294|
|Publication number||019643, 12019643, US 7760607 B2, US 7760607B2, US-B2-7760607, US7760607 B2, US7760607B2|
|Inventors||Chin-Huo Chu, Chun-Ying Chiang|
|Original Assignee||Mediatek Inc.|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (11), Classifications (9), Legal Events (2)|
|External Links: USPTO, USPTO Assignment, Espacenet|
This application is a continuation application and claims the benefit of U.S. application Ser. No. 10/905,428, filed on Jan. 4, 2005, now U.S. Pat. No. 7,349,312.
The present invention relates to optical storage devices, and more particularly, to a method and an apparatus for performing blank detection involved with Error Correction Code (ECC) decoding of information read from an optical storage disc.
Digital Versatile Discs (DVDs) and DVD drives are typical of the optical storage discs and optical storage devices, respectively. When the data flow generated by the optical storage device while reading the optical storage disc is interrupted, the decoder for decoding the data flow is not able to output a proper decoded signal. For example, the decoder for decoding the data flow will output a blank signal. A method for solving the data flow interruption problem mentioned above is to perform blank detection on the optical storage disc to control the decoder's decoding action on the data flow according to detection results of the blank detection. In this way, the decoder neither stops outputting signals nor outputs blank signals.
According to the blank detection method of the related art, when a processing unit of a front stage in the optical storage device detects the interruption of the data flow during a reading process, an optical pickup module of the optical storage device will be returned to an earlier location corresponding to data that has already been read but not yet buffered. That is, the optical storage device must reread and buffer the data that has not been buffered for further decoding. As the control of the blank detection mentioned above, the reading action of the optical pickup module, and the buffering control of the data flow correspond to independent control processes respectively, the optical storage device has to firstly perform the reading action of the optical pickup module, secondly perform the blank detection, then perform the reading action of the optical pickup module again, and finally perform the buffering control mentioned above.
As a result of the blank detection method of the related art, although the data flow interruption problem mentioned above is solved, a new problem of repeating the reading action of the optical pickup module is introduced. The optical storage device has to waste time moving the optical pickup module around the same region of the optical storage disc and rereading the same data stored in that region. An improved blank detection method is therefore required so that the performance of the optical storage device may be enhanced.
The present invention provides a method for performing blank detection on an optical storage disc. The method comprises: receiving information read by an optical storage device from the optical storage disc; and checking corresponding data of the information to operate blank detection.
Accordingly, the present invention further provides a circuit for performing blank detection on an optical storage disc. The circuit comprises: a buffering module for receiving information read by an optical storage device from the optical storage disc; and a checking module electrically connected to the buffering module for checking corresponding data of the information to operate blank detection.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
Please refer to
The buffering module 201 a includes a demodulator 202 coupled to the optical pickup module 110 for demodulating the data flow of the buffered data 252; a buffer controller 204 electrically connected to the demodulator 202 for controlling the data flow of the buffered data 252; a target search unit 206 electrically connected to the demodulator 202 for generating a logical address search signal 258 according to the buffered data 252 to control the buffer controller 204; an OR logic gate 208 electrically connected to the target search unit 206, the buffer controller 204, and the front stage circuit 112 for controlling the buffer controller 204 according to a physical address search signal 256 generated by the front stage circuit 112 and the logical address search signal 258; and a memory 210 electrically connected to the buffer controller 204 for storing the buffered data 252. The buffering module 201 a is capable of seeking locations within the buffered data 252 according to the physical address search signal 256 and the logical address search signal 258.
The checking module 201 b includes an AND logic gate 222 electrically connected to the demodulator 202 and the front stage circuit 112 for deriving blank header information 262 from a sync signal 254 outputted by the demodulator 202 according to a blank signal 260 generated by the front stage circuit 112; a threshold storage unit 226 coupled to the MPU 104 for storing two predetermined thresholds 264 and 266; a blank sector detection unit 224 electrically connected to the AND logic gate 222, the threshold storage unit 226, and the memory 210 for determining if a sector in the buffered data 252 is a blank sector according to the blank header information 262 derived by the AND logic gate 222 and the predetermined threshold 264, and generating at least one blank sector detection record 265 correspondingly; and a blank ECC block detection unit 228 electrically connected to the threshold storage unit 226 and the MPU 104 and coupled to the memory 210 through the ECC block controller 106 and the ECC decoder 108 for determining if an ECC block is a blank ECC block according to the blank sector detection record 265 and the predetermined threshold 266 during the decoding process of the decoder 108. As illustrated in
The predetermined thresholds 264 and 266 respectively utilized in Step 30 and Step 40 can be derived from experiments or trial tests. Additionally, both of the predetermined thresholds 264 and 266 can be adjusted by the MPU 104 using at least one MPU command, and the threshold storage unit 226 can be a register or a storage component that exists in the optical storage device 200. The existing register or storage component used as the threshold storage unit 226 is only an implementation choice and is not meant as a limitation to the present invention. According to another embodiment of the present invention, while both of the predetermined thresholds 264 and 266 are adjustable values, the predetermined thresholds 264 and 266 can be stored in the blank sector detection unit 224 and the blank ECC block detection unit 228, respectively. According to another embodiment of the present invention, the predetermined thresholds 264 and 266 can be fixed values stored in the blank sector detection unit 224 and the blank ECC block detection unit 228, respectively. According to yet another embodiment of the present invention, the blank sector detection unit 224 used in step 20 is capable of directly identifying the sync frame SF-I-J needing to be identified in the sync signal 254 as a normal sync frame or a blank sync frame according to whether the sync header of the sync frame SF-I-J is one of the normal sync headers SY0, SY1, . . . , and SY7 or one of the blank sync headers SY0′, SY1′, . . . , and SY7′. That is, the blank sector detection unit 224 of this embodiment may directly identify the normal sync headers SY0, SY1, . . . , and SY7 and the blank sync headers SY0′, SY1′, . . . , and SY7′.
It is an advantage of the present invention that when the blank detection of the optical storage disc is completed, the buffered data can be used as the data needed during error correction that will be performed according to error correction codes or used as the data needed for further decoding. Therefore, the present invention method and apparatus do not need to repeatedly perform the read action of the optical pickup module in the optical storage device. That is, during operations of the optical storage device, the blank detection and the buffering control are merged into one process to be performed together so that there is no need for extra movement and read action of the optical pickup module.
It is another advantage of the present invention that the first information can be the storage management information representing data recording states of the optical storage disc of the optical storage disc. Therefore, the speed of the blank detection can be increased. Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.
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|Cooperative Classification||G11B27/329, G11B27/3027, G11B2020/10675, G11B20/10527|
|European Classification||G11B27/32D2, G11B27/30C, G11B20/10C|
|Jan 25, 2008||AS||Assignment|
|Jan 20, 2014||FPAY||Fee payment|
Year of fee payment: 4